1. Field of the Invention
The present invention relates to a thermal displacement correction training unit for simulating on a computer a precision correction method and an adjustment method for a machine tool.
2. Description of the Related Art
When a work is processed using a machine tool, a microscopic displacement (hereinafter referred to as thermal displacement) is generated in the structure of the machine tool due to heat generated from the motor and the ball screws that form the machine tool and the processed portion of the work, cooling by the cooling oil or the cooling air, and disturbance by the outside air temperature. As a result, the point at which the work is processed slips, which becomes one of the major factors that affect the process precision. As a countermeasure for such thermal displacement, there is a method for correcting the slippage of the processing point by predicting the amount of heat generated at the time of processing and the amount of change in the structure (hereinafter referred to as thermal displacement correction).
As described above, thermal displacement varies upon the reception of the effects by the outside air temperature and the cooling oil, and therefore, even the same machine has a different amount of thermal displacement depending on the situation. In the case where the precision in the processing of the work at the time of thermal displacement correction is not sufficient after actual measurement of the dimensions of the work that has been processed, an operation may be carried out for closing the gap between the amount of thermal displacement and the amount of thermal displacement correction by changing the amount of thermal displacement correction depending on the situation (hereinafter referred to as adjustment of thermal displacement correction). As for such an adjustment of thermal displacement correction, Japanese Unexamined Patent Publication 2014-54700 discloses a method for allowing an operator to move an image of the work or an image of the tool within the screen for visual adjustment.
However, the following problems can be cited as problems to be solved in the prior art.
The amount of thermal displacement and the amount of correction thereof are generally minute, which means the amount of adjustment for correction is also minute, and thus, it is difficult to visually determine whether or not the adjustment of the correction amount is precise. The technology in Japanese Unexamined Patent Publication 2014-54700 does not disclose a method for determining whether or not the adjustment of thermal displacement correction is appropriate. It is necessary to sufficiently train the operators who operate a machine tool for the operation of adjusting the thermal displacement correction so that the adjustment of thermal displacement correction can be appropriately carried out.
It is also necessary to prepare actual machine tools in order to train the operators so that the operators can learn a method for using thermal displacement correction. However, machine tools are generally expensive, which makes it economically difficult to prepare machine tools for the purpose of training for thermal displacement correction. There is also a risk of affecting other parts of the process in temporarily stopping for training the processing of a work with an actual machine tool that is being used for the processing of a work.
As a result, it is not practical for an operator to have an opportunity to be trained for thermal displacement correction using an actual machine tool.